CONTROLLING DISPLAY BRIGHTNESS BASED ON IMAGE CAPTURE DEVICE DATA
A system and method for controlling the brightness level of an electronic display. An image capture device in proximity to the electronic display is used to capture images and/or video of the ambient environmental conditions local to the electronic display. The images and/or video is analyzed to determine the nature of the environmental conditions, and adjustments to the brightness level of the electronic display are made in consideration of said environmental conditions. In some embodiments, the images and/or video captured by the image capture device may be compared to stored images representative of different environmental conditions.
Exemplary embodiments described and shown herein generally relate to a system and method for controlling the brightness of an electronic display based on various metrics.
BACKGROUNDElectronic displays, once used primarily for only indoor entertainment purposes, are now also being utilized for indoor and outdoor advertising/informational purposes. For example, various types of flat panel electronic displays are now being used to present information and advertising materials to consumers in locations outside of their own home, such as within airports, arenas, stadiums, and restaurants/bars, at gas station pumps, on billboards, and even in shifting locations via mobile electronic displays on the tops of automobiles or on the sides of trucks.
The rapid development of flat panel electronic displays has allowed users to mount such displays in a variety of locations that were not previously possible. Further, the popularity of high-definition (HD) television has increased the demand for larger and brighter displays, especially large displays that are capable of producing HD video. The highly competitive field of consumer advertising has also increased the demand for large displays that are located outdoors and sometimes exposed to direct sunlight or other high ambient light conditions (e.g., light from street lights, building signs, vehicle headlights, and other displays). In order to be effective, outdoor displays must compete with the ambient natural light to provide a clear and bright image to a viewer.
SUMMARY OF THE GENERAL INVENTIVE CONCEPTThe various exemplary embodiments described and shown herein are directed to a system and method for controlling the luminance of an electronic display based on a combination of metrics. Exemplary systems and methods are configured to appropriately illuminate an electronic display based on local ambient conditions to maximize visibility while optimizing power usage. For example, in order to conserve electrical energy, a given electronic display may be driven at a higher brightness level under bright ambient conditions to maximize visibility, and may be driven at a lower brightness level under dim ambient conditions.
In some embodiments, control of the brightness level may be based on the time of day, which is compared with sunrise/sunset data associated with the geographic location of the display. Generally speaking, an ambient light sensor is not necessary. In such exemplary embodiments, the system may include a location detection device, such as but not limited to a Global Positioning System (GPS) device, that determines the geographic location of the display. Sunset and sunrise transition periods may be calculated by the system based on the location of the display and may be used to gradually adjust the display brightness up/down during these transition periods.
In some other exemplary embodiments, electronic display brightness control may employ a camera that is positioned in close proximity to the display and is configured to periodically capture a still image or video of the weather conditions to which the display is exposed. A processor may be utilized to subsequently analyze the captured image or video data to determine the local weather conditions and, when necessary, to appropriately adjust the brightness of the electronic display. Further embodiments may also access local weather information and adjust the brightness level of an electronic display based on the percentage of cloud cover or other weather conditions. Weather conditions of interest to an exemplary system and method embodiment may include, but are not limited to, precipitation, fog, haze, and cloud, all of which can affect the ambient lighting conditions to which a given electronic display is exposed throughout the day (or night).
In addition to the features mentioned above, other aspects of the inventive concept will be readily apparent from the following descriptions of the drawings and exemplary embodiments, wherein like reference numerals across the several views refer to identical or equivalent features, and wherein:
Exemplary system and method embodiments are described more fully hereinafter with reference to the accompanying drawings, in which exemplary such embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so as to thoroughly convey the scope of the inventive concept to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.
The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the inventive concept. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, indicate the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Exemplary system and method embodiments are described herein with reference to illustrations that are schematic in nature and, as such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the inventive concept should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Referring now to the drawings,
A timing and control board (TCON) 108 may be electrically connected to the electronic display 104. A video player 110 may be electrically connected to the TCON 108 and to a system control board 112. The video player 110 and TCON 108 may be configured to display still or video images on the electronic display 104 as directed by the system control board 112. The images or videos may be stored on an electronic storage device 118. In some exemplary embodiments, the electronic storage device 118 may be local to the electronic display assembly 100. In other exemplary embodiments, the electronic storage device 118 may be a networked device that is located remotely from the electronic display assembly 100.
The system control board 112 may be configured to provide display setting instructions for the electronic display 104. The display settings may include, for example and without limitation, what images are to be displayed, in what order the images are to be displayed, the length of time the images are to be displayed, etc. The system control board 112 may additionally provide appearance setting instructions for the electronic display 104. The appearance settings may include, for example and without limitation, levels for brightness, color saturation, warmth, volume, contrast, etc. The appearance and display settings may be pre-programmed or may be altered at any time, such as by a remote user.
The camera 102 may be electrically connected or otherwise in communication with the system control board 112. A processor 106 of the system control board 112 may be provided with captured image and/or video data from the camera 102 and may be configured to perform an analysis on said data to determine the ambient weather conditions local to the electronic display 104. For example, the processor 106 may be programmed, or may operate in conjunction with software, to determine weather conditions by direct analysis of the images/video. The analysis performed by the processor 106 may be carried out using shape recognition, histogram analysis, motion detection, and other imaging processing and analysis techniques, software, and systems.
In some exemplary embodiments, a number of sample images of various weather conditions may be previously stored and made accessible by the processor 106. In such an embodiment, an image/video captured by the camera 102 may be compared to the sample images and/or sample video using, such as by employing image similarity analysis techniques, software, and systems. If a captured image/video has a sufficient level of similarity to a stored image/video of a particular weather condition, a predetermined adjustment may be made to the brightness or other settings of the electronic display 104 based on that weather condition. In other exemplary embodiments, the brightness or other settings of the electronic display 104 may be adjusted based on the percentage or level of similarity between a given captured image/video and the sample images/videos.
Whether a direct analysis of a captured image/video is performed, or a similarity analysis is performed between a captured image/video and stored images/videos of known weather conditions, an exemplary system and method embodiment is able to determine/identify a number of different weather conditions. Such weather conditions that are identifiable by the processor 106 may include, but are not limited to, rain, snow, hail, sleet, other precipitation, sunlight, cloud cover, cloud ceiling, fog, haze, large light-blocking objects, etc.
The processor 106 may be placed upon and in electrical connection with the system control board 112. Data pertaining to the results of the image analysis may be sent to the system control board 112 and the system control board may adjust the appearance settings of the electronic display 104 based on the image analysis. In exemplary embodiments, if the image analysis reveals weather conditions likely to result in dim ambient lighting conditions, such as but not limited to, rain, cloud cover, low cloud ceiling, snow, hail, sleet, other precipitation, fog, haze, or the like, the system control board 112 may direct the electronic display 104 to be driven at a higher brightness level. If, on the other hand, the image analysis reveals weather conditions likely to result in brighter ambient lighting conditions, such as but not limited to, sunshine, little cloud coverage, high cloud ceiling, and the like, the system control board 112 may direct the electronic display 104 to be driven at a lower brightness level. In some exemplary embodiments, the processor 106 may translate the image analysis into a weather factor number as described herein.
The system control board 112 may be electrically connected to a network interface device 114. The network interface device 114 may facilitate a connection with, and communication over, a communications network 116 such as, but not limited to, an intranet, the Internet, the world wide web, a cellular network, or the like. This connection may permit a remote user to alter the appearance settings and display settings, and to monitor the performance and operation of, the electronic display assembly 100.
The system control board 112 may additionally be electrically connected to a location detection device 120. In some exemplary embodiments, the location detection device 120 may be a GPS-enabled device. In other exemplary embodiments, the location detection device 120 may operate by the use of multilateration, trilateration, etc., of radio tower signals, such as but not limited to, cellular network towers, Wi-Fi routers, and the like. Those having ordinary skill in the art will recognize any location detection method may be utilized.
A variety of different electrical inputs/outputs are also shown in
A backlight sensor 29 may be placed within the backlight cavity of the electronic display assembly 200 to measure the brightness level within the backlight cavity. Additionally, a display light sensor 40 may be positioned in front of the display 24 in order to measure the brightness level of the display 24. Either sensor can be used in a traditional feed-back loop to evaluate the control signals being sent to the power modules 21 and the resulting backlight brightness intensity or display brightness intensity generated in response.
Information for monitoring the status of the various display components may be transmitted through either of the two data interface connections 32 and 33, so that the user can be notified when a component may be functioning improperly, about to fail, or has already failed and requires replacement. The information for monitoring the status of the display may include, but is not limited to: power supply status, power supply test results, AC input current, temperature sensor readings, fan speed, video input status, firmware revision, and light level sensor readings. Also, the user may adjust settings including, but not limited to: on/off, brightness level, various alert settings, IP address, customer defined text/video, display matrix settings, display of image settings via OSD, and various software functions. In some embodiments, these settings can be monitored and altered from either of the two data interface connections 32 and 33.
Once the location of the electronic display is determined, the sunset and sunrise times for this location are preferably determined. The timing for performing this step can vary. In some embodiments, determining the sunset and sunrise times could be performed only once, with 365 days of data being used for the display throughout the remainder of the display's lifetime. Alternatively, this step could be performed annually, monthly, weekly, or even daily. This step can also be performed in a number of ways. For example, when given a physical address, the system can determine the sunrise/sunset times based on the address and store the times, such as on the electronic storage of the display controlling assembly 20. Alternatively, when given latitude/longitude coordinates, the system can determine the sunrise/sunset times based on said coordinates and store the coordinates within the electronic storage of the display controlling assembly 20. The location data can be converted to sunrise/sunset times by accessing any number of online databases, including but not limited to: www.sunrisesunset.com, www.suncalc.net, and various NOAA online tools. Additionally, the latitude and longitude data can be used to calculate sunrise/sunset times based on the sunrise equation:
cos ωo=tan φ×tan δ (1)
where:
ωo is the hour angle at either sunrise (when negative value is taken) or sunset (when positive value is taken);
φ is the latitude of the observer on the Earth; and
δ is the sun declination.
It should be noted that the steps of determining geographical location data for a display and determining approximate sunrise/sunset times based on the geographical location data, may be performed before the display is shipped to its actual location. In other embodiments, the display may be installed within its actual location prior to performing these steps.
Once the approximate sunrise/sunset times are determined (and preferably stored at the display or otherwise), the system then determines the current time and also whether it is currently night or day. Although the logic of
The relative daytime level and nighttime level for the backlight may be selected in this embodiment through a simple binary operation, using a first backlight brightness level value appropriate to nighttime operation and a second backlight brightness level value appropriate to nighttime operation. The system may then supply as much power as necessary to the backlight 23 in order to produce the desired brightness level value at the backlight sensor 29. The power levels may be adjusted using feedback from the backlight sensor 29 to ensure that the desired brightness level of the backlight 23 is maintained. Alternatively, the desired brightness level can be measured based on the brightness level of the display 24, as measured by the light sensor 40. The light sensor 40 can also provide feedback to the system to ensure that the proper amount of power is being sent to the backlight 23 so that adequate display brightness levels. In still other embodiments, the relative daytime brightness level and nighttime brightness level for the backlight may be preprogrammed based on known data or assumptions about the proper power level that is required to achieve the desired brightness level.
Note that the dashed lines in
It should also be noted that when driving the backlight of an electronic display (or an electronic display without a backlight) based on location data and/or time of day, an exemplary system does not have to choose one brightness level for daytime and one brightness level for nighttime (although some embodiments employ this method). Instead, an exemplary system may make slight adjustments to the brightness level based on the current time of day. For example, while 9:15 a.m. and 1:30 p.m. would each normally occur after sunrise and before sunset, the system may drive the backlight to produce different brightness levels for each time. Thus, as used herein, the terms “nighttime level” and “daytime level” may represent brightness level values that are based on a specific time of day, and a brightness level for a given time of day may be obtained from a lookup table or through an equation/calculation. In this manner, given the assumption that there will be more ambient light present during the afternoon than in the early morning (or late evening for that matter), a system might drive a display at a brightness level that is higher at 1:30 p.m. than at 9:15 a.m., despite the fact that both times occur during the daytime.
It should also be noted that the transition from a “nighttime” brightness level to “daytime” brightness level preferably does not occur in a drastic manner, where an abrupt change or flicker in the display might be observed by a viewer. Rather, it is preferable that such a change in display brightness level occurs in an incremental or ramped fashion, where the brightness level does not suddenly shift to a new value, but instead gradually changes to a new value over some period of time that would make the change less noticeable to a viewer.
An exemplary alternative method of controlling electronic display brightness using an Artificial Ambient light Sensor (AAS) technique during sunset/sunrise transition times and a nighttime/daytime level for other times is represented by the logic flow chart of
(1) Desired Nighttime Level—the desired display brightness at nighttime;
(2) Desired Daytime Level—the desired display brightness during the daytime;
(3) High Ambient Reading (HA)—the approximate raw data value corresponding to the highest ambient light levels for the display environment, which may be preprogrammed based on known data or assumptions about the approximate high ambient reading for the display environment;
(4) GPS coordinates for the display location or the address/city/state of the display location;
(5) Sunrise transition period (tsr)—the amount of time (usually measured in seconds) to transition from nighttime to daytime; and
(6) Sunset transition period (tss)—the amount of time (usually measured in seconds) to transition from daytime to nighttime.
For a method employing an AAS technique, the AAS data can be calculated during the sunrise transition period using the following equation:
AAS for sunrise=(ti*HA)/tsr (2)
where ti is the time in transition (i.e., ti varies between zero and tsr).
Similarly, the AAS data for the sunset transition period can be calculated using the following equation:
AAS for sunset=HA−(ti*HA)/tss (3)
where ti is the time in transition (i.e., ti varies between zero and tss).
Once the AAS data for either transition period has been calculated, the desired brightness level can be determined from any of the ambient light vs. display brightness relationships described above. In some embodiments, the sunset transition period and the sunrise transition period may be similar or substantially the same. In this case, it may not be necessary to have two transition periods. Instead, one transition period may be used.
In another exemplary embodiment, the system and method can also utilize local weather information to further tailor the display brightness. Such local weather information may be obtained from available web APIs or other online weather information which may be accessed at a predetermined time interval (e.g., every 15 minutes). In such an exemplary embodiment, a weather factor (WF) is calculated as:
WF=4*Ci (if it is daytime or any transition period) (4)
where Ci=clearness percentage with a higher percentage representing a clear sky and a lower percentage representing a large amount of cloud cover. The inverse could also be used, where a higher percentage represents more cloud cover and a lower percentage represents less cloud cover. Either technique would be well understood by a person of ordinary skill in the art.
In this exemplary embodiment, the AAS data can be calculated during the sunrise transition period according to the following equation:
AAS for sunrise=(ti*(HA*WF))/tsr (5)
Similarly, the AAS for the sunset transition period can be calculated according to the following equation:
AAS for sunset=(HA*WF)−(ti*(HA*WF))/tss (6)
If it is daytime, AAS=HA*WF.
If it is nighttime, AAS=0.
Once AAS for either transition period or the daytime has been calculated, the desired brightness level can be determined from any of the ambient light vs. display brightness relationships described above.
It has been found that the human eye is more sensitive to brightness variations in low ambient light environments than in high ambient light environments. Therefore, in some embodiments, a more aggressive display brightness level response may be desired at lower ambient light levels. In this regard,
It should be noted that while the curves of
As an example, during the daytime (i.e., not within either transition period or nighttime) and where the local weather information indicates that it is overcast and raining, relevant exemplary calculations might be:
Ci=10% clearness percentage
HA=500
Weather factor=4*0.10=0.40
AAS=500*0.40=300
Desired Display Brightness˜=1040 nits (from FIG. 6 with an ambient light value of 300); or Desired Display Brightness˜=1965 nits (from FIG. 7 with an ambient light value of 300).
Note that without correction for local weather conditions, the daytime value would likely be 500, which would mean the Desired Display Brightness˜=2500 nits. Consequently, it can be clearly understood that this exemplary method of controlling electronic display brightness can significantly reduce the amount of electrical energy that will be used to power the display (or backlight) by accounting for the reduced ambient light level resulting from an overcast sky.
As another example of the same exemplary method of controlling electronic display brightness, if the electronic display is halfway through a sunrise or sunset transition, the calculated light sensor value and corresponding desired brightness might be:
tsr=1800 seconds
ti=900 seconds
HA=500
Weather factor=4*0.10=0.40
AAS=(900*500*0.40)/1800=100
Desired Display Brightness˜=465 nits (from FIG. 6 with an ambient light value of 100); or Desired Display Brightness˜=1030 nits (from FIG. 7 with an ambient light value of 100).
Without correction for local conditions, the AAS value would likely be 250 which corresponds with a Desired Display Brightness˜=850 nits.
In an exemplary embodiment employing the logic of
The system may adjust the display brightness according to the current time as previously described. The system may check to ensure that the current date is the same as the date used in determining the approximate sunrise and sunset times as the sunrise and sunset times vary slightly on a daily basis. If the date has changed, the system may recalculate the approximate sunrise and sunset times. However, in other exemplary embodiments, the period between recalculating the approximate sunrise and sunset times may be any amount of time, such as days, weeks, months, or years.
If the date has not changed, the system may check to see if a predetermined allotted amount of time has passed. If not, then the system may return to checking the current date. If a predetermined allotted amount of time has passed, the system may capture an image and/or video of the current weather conditions. The image and/or video may be analyzed to determine the current weather conditions and the electronic display (or backlight) may be driven at an increased or decreased brightness level to adjust for the weather conditions as previously described. The system may then return to determining the current date and time.
In the particular exemplary embodiment represented in
A table liken that depicted in
According to an exemplary embodiment that applies the logic of
As shown in
Having shown and described various exemplary embodiments of the invention, those skilled in the art will realize that many variations and modifications may be made to affect the described embodiments while remaining within the scope of the inventive concept. Additionally, many of the elements described above may be altered or replaced by different elements which will provide the same result and fall within the spirit of the inventive concept. It is the intention, therefore, to limit the inventive concept only as indicated by the scope of the following claims.
Claims
1. A system for controlling the brightness of an electronic display, the system comprising:
- an image capture device in proximity to the electronic display and configured to capture images and/or video of local environmental conditions; and
- a controller in communication with the image capture device and the electronic display, the controller operable to adjust the brightness of the electronic display;
- wherein the controller is configured to determine the environmental conditions local to the electronic display by analyzing the images/video captured by the image capture device, and to adjust the brightness level of the electronic display in response to the determined environmental conditions.
2. The system of claim 1, further comprising a database of stored images representative of different environmental conditions, the database accessible by the controller.
3. The system of claim 2, wherein the controller is further configured to determine the environmental conditions local to the electronic display by comparing images/video captured by the image capture device to images in the database.
4. The system of claim 2, wherein the images in the database are preprogrammed.
5. The system of claim 2, wherein the controller is configured, during a device setup procedure, to instruct the image capture device to periodically capture images of the environmental conditions local to the electronic display and to populate the database with said images.
6. The system of claim 1, further comprising a display light sensor for detecting the brightness level of the electronic display, the light sensor in communication with the controller.
7. The system of claim 1, further comprising a backlight light sensor for detecting the brightness level of a backlight associated with the electronic display, the light sensor in communication with the controller.
8. The system of claim 1, further comprising a lookup table of desired display brightness values versus various ambient light levels, the lookup table accessible by the controller.
9. The system of claim 1, further comprising a location detection device configured to determine the geographic location of the electronic display and to communicate said location to the controller.
10. The system of claim 1, wherein the controller is further configured to determine a parameter selected from the group consisting of the current date, the current time, the geographic location of the electronic display, the approximate sunrise and sunset times, and various combinations thereof.
11. The system of claim 1, wherein the electronic display is of a type selected from the group consisting of a liquid crystal display with a backlight, a plasma display, a light-emitting polymer display, and an organic light emitting diode display.
12. A system for controlling the brightness of an electronic display based on image capture device data, the system comprising:
- an image capture device in proximity to the electronic display and configured to capture images and/or video of local ambient environmental conditions;
- a system controller in communication with the image capture device and the electronic display, the system controller operable to adjust the brightness of the electronic display; and
- a database of stored images representative of different environmental conditions, the database accessible by the system controller;
- wherein the system controller is configured to determine the environmental conditions local to the electronic display by comparing images and/or video captured by the image capture device to images in the database, and to adjust the brightness level of the electronic display in response to the determined environmental conditions.
13. The system of claim 12, further comprising a display light sensor for detecting the brightness level of the electronic display, the light sensor in communication with the system controller.
14. The system of claim 1, further comprising a location detection device configured to determine the geographic location of the electronic display and to communicate said location to the system controller.
15. The system of claim 1, wherein the electronic display is of a type selected from the group consisting of a liquid crystal display with a backlight, a plasma display, a light-emitting polymer display, and an organic light emitting diode display.
16. A method for controlling the brightness of an electronic display, the method comprising:
- placing an image capture device in proximity to the electronic display, the image capture device configured to capture images and/or video of local environmental conditions;
- associating a controller with the electronic display, the controller in communication with the image capture device and the electronic display, and operable to adjust the brightness level of the electronic display;
- configuring the controller to determine the environmental conditions local to the electronic display by analyzing the images/video captured by the image capture device; and
- when the controller determines an adjustment is necessary, using the controller to adjust the brightness level of the electronic display based on the determined environmental conditions.
17. The method of claim 16, further comprising:
- providing a database of stored images representative of different environmental conditions; and
- placing the database in accessible communication with the controller.
18. The method of claim 17, further comprising determining the environmental conditions local to the electronic display controller by using the controller to compare images/video captured by the image capture device to images in the database.
19. The method of claim 17, further comprising running a device setup procedure, wherein the image capture device periodically captures images of the environmental conditions local to the electronic display and populates the database with said images.
20. The method of claim 19, further comprising storing the images in the database according to existing ambient light conditions or desired display brightness level.
21. The method of claim 16, further comprising using the controller to:
- determine the current date;
- determine the current time; and
- adjust the brightness level of the electronic display based on the current time before making any brightness adjustments based on the local environmental conditions.
22. The method of claim 21, further comprising using the controller to:
- determine the geographic location of the electronic display; and
- determine the approximate sunrise and sunset times based on the date and the geographic location of the electronic display.
23. The method of claim 21, further comprising using an AAS technique for calculating the amount of ambient light present at the location of the electronic display.
24. The method of claim 23, wherein the calculated ambient light level is used in conjunction with the determined environmental conditions in adjusting the brightness level of the electronic display.
25. The method of claim 24, wherein the controller accesses a lookup table of desired display brightness values versus various ambient light levels when determining an adjustment to the brightness level of the electronic display.
Type: Application
Filed: Jul 7, 2017
Publication Date: Jan 11, 2018
Patent Grant number: 10586508
Inventor: William Dunn (Alpharetta, GA)
Application Number: 15/644,707